X-ray Facilities

Xradia MicroXCT-400 Micro-Computed TomographyThe MicroXCT uses X-rays to visualise the surface and internal structures of a specimen in three dimensions, typically without extensive or destructive specimen preparation. The samples are imaged at atmospheric pressure. The maximum sample size that can be imaged is 500 mm diameter by 400 mm height. The instrument is capable of submicron resolution (0.7 µm) – at this resolution the sample width needs to be 600 µm. The X-ray energy can be varied between 40 kV and 150 kV. The instrument can collect images by absorption contrast as well as 'phase contrast' making it suitable to image a wide range of specimens including: both hard and soft biological tissues as well as minerals, ceramics, polymers etc.

Xradia NanoXCT-100 Nano-Computed TomographyThe NanoXCT is a specialised instrument that can scan small samples with a resolution down to 50 nm. It can non-destructively obtain 3-D information from internal structures at 2 volumes: 64 µm3 (resolution 150 nm) and 16 µm3 (resolution 50 nm). Sample sizes need to be 100 µm or less to achieve instrument resolution. It can image in absorption mode as well as phase contrast (this greatly improves image contrast for low-atomic-number samples and should greatly enhance the ability to scan soft biological specimens and polymers). The X-ray source operates at 8 kV. Instrument scan times can be quite long and would typically be two days for optimal results.

Skyscan 1072 Micro-Computed TomographyThe Micro-CT uses a microfocus X-ray source to visualise the surface and internal structures of a specimen in three dimensions, without extensive or destructive specimen preparation. The maximum resolution attainable with the Micro-CT is approximately 2 µm, however this depends on the size of the sample being scanned. At lower resolutions (24 µm) sample sizes may be as big as 5 cm3, while at higher resolutions the maximum sample size may be 4-5 mm3. The energy of the X-ray beam is also variable (up to 100 KeV 98 µA) to adjust for specimens of various densities.

During scanning, the specimen is rotated in small increments over 180°C or 360°C and an X-ray projection image is captured at each step. After scanning, a cone-beam reconstruction program is used to turn the projection images into a stack of 1000 cross-sections. These cross-sections can be used with a variety of image analysis and 3-D volume rendering software packages for 2-D or 3-D morphometrical analysis, or to produce 3-D images and animations.

Micro-CT relies on a density difference between the structure of interest and the surrounding material. Porous materials (minerals, ceramics, polymers) are particularly suited to this method. Other applications include bone, teeth, lung tissue, archaeological and paleontological specimens, coral and wood.